A recent multi-color embroidery sewing machine is provided with embroidery color display data and embroidery data for each of embroidery areas, and is capable of changing colors so as to finish embroidery in any color by selecting and specifying embroidery areas that are displayed, and by having color specification for the embroidery areas and embroidery data for the selected embroidery areas be recorded.
One method for utilization of this function is to use multi-scale monotone color embroidery specification, in contrast to original multi-color embroidery specification. However, it is not easy for a user to determine the multi-scale color by the user's own. In order to convert embroidery color display data of multiple colors into monotone data, it is necessary to first find out RGB values of all thread types used in a pattern, for example, and then determine thread colors taking balance as a whole into account. Conventionally, it has been extremely difficult to convert embroidery color display data of multiple colors into monotone data as described above.
Further, in addition to simple conversion of embroidery color display data of multiple colors into the monotone data, there is a case in which single-color embroidery without gradation using embroidery color display data of multiple colors is desired, and a case in which embroidery with a fewer number, although multiple, of shades in gradation using embroidery color display data of multiple colors is desired. For example, in a case of performing embroidery in one color, it is often not possible to provide an intended pattern as the pattern may go out of shape when colors of all threads in embroidery color display data of multiple colors are simply changed into the same color. Further, when the number of shades in gradation is desired to be decreased, it is necessary to set embroidery areas to which different colors are specified to have the same gradation level. However, it is difficult to determine which colors should be set to have the same gradation level.
Patent Literature 1 discloses a thread-color setting device that changes thread colors for embroidery based on a sensitivity word that has been input.
However, with the device disclosed in JP-A-11-114259, while it is easily possible to change the thread colors, it is not possible to decrease a number of colors (number of threads). In the case of monotone, to decrease the number of colors means to decrease a number of shades in gradation. In a case in which monotone embroidery is attempted using the device disclosed in Patent Literature 1, it is necessary to prepare a large number of threads of the same color but with different intensity or the like if embroidery data of a design with a large number of colors is used. In monotone embroidery, using a large number of threads is often ineffective, and a result worth the labor required for preparation may not possibly be obtained.